Major depression is a serious, potentially life-threatening illness that can cause significant pain and suffering. It afflicts up to 50% of patients who are seen in the primary care setting. However, it is a remarkably treatable disorder, once it is recognized. The mainstay of treatment is education about the illness, brief supportive counseling, and antidepressant medication. This monograph is a synopsis of a book, Outpatient Management of the Depressed Patient, recently published on this subject. We focus on how to diagnose and treat major depression in the primary care setting, in which the vast majority of patients with this condition are seen. We review the condition itself, how to establish the diagnosis, what education and brief supportive counseling are needed and how to provide them, how to select an antidepressant, and how to use the drug to induce and maintain remission.